1. Field of the Invention
This invention relates to compositions and methods useful in inhibiting the growth of cariogenic bacteria and the formation of plaque on teeth in an oral environment.
2. Prior Art
The prevention of the formation of dental plaque is a highly desired result. Dental plaque results when cariogenic bacteria (e.g., Streptococcus Mutans) collect on colonies on the surface of teeth and form a tenacious deposit thereon. The presence of both the bacteria and the deposits is extremely detrimental to the health of the teeth. Thus, if the cariogenic bacteria and the plaque formation are not checked they may result in infected gingival tissue, the formation of dental caries and periodontal disease. In extreme cases they may ultimately result in the loss of teeth.
To overcome these problems many attempts have been made to control cariogenic bacteria and the formation of plaque on teeth. For example, fluoride solutions or gels have been used. Treatment with these materials is typically performed in a dental office at periodic, but not frequent, intervals. The primary objective of these treatments is to render the tooth enamel more resistant to the acid action caused by plaque. Such treatments do not, however, result in plaque control for an extended period since plaque reestablishes itself on the teeth shortly after ingestion of food.
Even when the frequency of application of such solutions and gels is increased only partial control has been shown. For example, studies wherein a fluoride-containing solution (1% fluoride concentration) was applied four to five times in the course of a year have demonstrated that this technique had only limited success due to the rapid reestablishment of plaque in the oral cavity. Moreover, the daily application of a fluoride gel by means of a custom-fitted polyvinyl mouthpiece for a period of twenty-one months also showed no substantial change in plaque formation among treated and untreated patients. See "Clinical Anticaries Effect of Repeated Topical Sodium Fluoride Application by Mouthpiece", Journal of the American Dental Association, V. 75, No. 3, September, 1967, pp. 638-644.
Other attempts at inhibiting the formation of plaque have also been made. For example, U.S. Pat. No. 3,733,399 describes toothpaste compositions which contain the enzyme invertase as the active ingredient. Another approach is disclosed in U.S. Pat. No. 3,894,147 wherein the application to teeth of a dialkyl pyrophosphate having from about 8 to 14 carbon atoms in the alkyl groups is described as useful in inhibiting plaque formation.
Each of the foregoing approaches require frequent (e.g., daily) use, in order to effectively control the cariogenic bacteria and inhibit the formation of plaque over an extended period of time. The present invention, however, provides compositions which are useful in controlling cariogenic bacteria and inhibiting the formation of plaque over an extended period of time despite relatively infrequent application to teeth.